Therapeutic product and process of preparing it



Patented Oct. 29, 1940 UNITED STATES PATENT OFFICE THERAPEUTIC PRODUCTAND PROCESS OF PREPARING IT George B. Walden,

Eli Lilly and Company, poration of Indiana Indianapolis, Ind., assignorto Indianapolis, Ind., a cor- 8 Claims.

It is the object of my invention to obtain a more effective utilizationof Insulin; and, more specifically, to make an Insulin product which I Vis effective over a longer period of time than is ordinary Insulin.

I have found that Insulin will somehow combine with the reaction productof guanidine and certain of its derivatives with formaldehyde and itspolymers, to form a product, possibly a chemical or physical compound ofsome nature, which when administered subcutaneously or intramuscularlyproduces a reduction in the bloodsugar level over a longer period oftime than does the similar administration of the Insulin alone.

The guanidine derivatives which I may use include not only guanidinesalts, by which I mean addition products formed by the reaction ofguanidine with an acid, such for instance as guanidine sulfate,guanidine hydrochloride, guanidine nitrate, and guanidine carbonate, butalso various other substances containing the guanidine nucleus (1) andcapable of forming with formaldehyde and its polymers a reaction productwhich modifies the Insulin to prolong the physiological action thereof.Usually in that reaction product the several bonds of the guanidinenucleus are satisfied with substituents, either hydrogen or a radio cal,which confer on the reaction product the characteristic ability to forma precipitate with Insulingenerally at about pH 7.0, by which I meanbetween pH 6.5 and pH 7.5.

The term formaldehyde and its polymers includes such products asparaformaldehyde and other polyoxymethylenes which may be formed bypolymerization from formaldehyde. The reaction product of guanidine andthe aforesaid I derivatives thereof with formaldehyde and its polymersmay be obtained, desirably under slightly alkaline conditions, by simplyletting the two reactants stand for a period of several hours in contactwith each other, or by heating the two reactants together. For instance:

Example I .To 10 gm. of guanidine carbonate I may add about cc. offormaldehyde, or about 8 gm. of paraformaldehyde in about 12 cc. ofwater, and either let the whole stand for a while, as over night, orelse boil the mixture until the reaction is complete, which usuallyrequires several minutes. The reaction which occurs, in this and theother examples given, results in the formation of a product the exactnature of which 1 am not now prepared to state, but which forconvenience I shall generically 5 refer to herein simply as the reactionproduct.

The reaction product of guanidine carbonate and formaldehyde, when insolid form, is white in color, soluble in water, and substantiallyinsoluble in alcohol and ether. 10

Example II.-To 10 gm. of guanidine sulfate (or of guanidinehydrochloride or guanidine nitrate or guanidine) I may add about 20 cc.of 40% formaldehyde, and also about 10 cc. of ammoniumhydroxide, andboil the mixture until 5 the formaldehyde-guanidine reaction iscomplete.

Example III.-To 10 gm. of decamethylenediguanidine dihydrochloride(known as Synthalin),

lfiIH 1 1 in NH 2 NH2-oN-(oH2),0Nt:-NH2 -2HOl I may add about 20 cc. of40% formaldehyde, and about 10 cc. of ammonium hydroxide; and boil'themixture until the reaction is complete. The reaction product, like thoseof Examples I and II, is broadly speaking a guanidine-formaldehydeproduct; and I mean to include such products when I use the termreaction product.

Example IV.-I follow the procedure of Example III, save that as theguanidine derivative I use 4.4'-diguanidodiphenyl dihydrochloride,

NE H

In order to carry out the reaction, it is desirable that slightlyalkaline conditions be maintained. When guanidine carbonate is used, theinherent alkalinity of the carbonate is usually sufficient. Whenguanidine salts which are not inherently alkaline are used, however, Imay produce the desired slight alkalinity in any suitable way, as byadding ammonium hydroxide tothe mixture.

In all of these examples, just as in Example I, I may useparaformaldehyde or other polyoxymethylene instead of formaldehyde.

Other variations of producing the reaction product may be made, but theexamples given are believed to be sufficient to indicate their generalcharacter.

The proportions given in the examples are merely illustrative, and notlimiting. At present I prefer that there be an excess of theformaldehyde or its polymers, but I do not consider that essential.

The process of forming such a reaction product, and the reaction productitself, form the subject-matter of my co-pending application Serial No.127,528, filed February 24, 1937.

By evaporating the solution to dryness at room temperature, a solid maybe obtained containing the reaction product. The solid reaction product,obtained in any desired way from the solution, may be used with theInsulin to produce the desired final product.

Instead of separating the reaction product from the solution in which itwas formed, I may use that solution with the reaction product in it asthe substance to be mixed with the Insulin.

However the reaction product is used, whether in solid form or in theoriginal solution, the reaction product, and Insulin of any character,are suitably mixed in any desired way. The proportions may vary widely,depending on the final results desired. When it is desired that theInsulin effect be greatly prolonged, I prefer that there be at leastenough, and desirably rather more than enough, of the reaction productto cause a maximum amount of precipitate when by adjusting the hydrogenion concentration a precipitation is caused-such as usually occursbetween pH 6.0 and pH 8.0. For instance, assuming that there are about20 units per mg. of solid Insulin, which is within the usual range ofordinary commercial Insulin, in such cases I desirably add at least 1mg. of the reaction product for each 10 mg. of Insulin.

I may vary the product thus formed between Insulin and the reactionproduct by the addition of another ingredient if desireda metal of theclass consisting of zinc, nickel, cobalt, cadmium, calcium, iron,copper, and aluminum, preferably in the form of a salt. That is, theproduct may be used with or without the addition of such metal; but Ihave found it desirable from several standpoints to have a metalpresent, especially zinc. Good results are obtainable with as little as0.025 mg. of zinc per 100 units of Insulin; and I desirably add at leastthat much. Larger amounts of metal may be used, and indeed somewhatlarger amounts seem to be desirable; with no upper limit exceptincreased toxicity and untoward local reactions, which should beavoided, to which end I desirably keep the metal present below about 1.0mg. per 100 units of Insulin.

I am not the first to put together a metal and Insulin to produce aprolongation of Insulin effect, as that has been done by David A. Scottand Albert M. Fisher. But, so far as I know, I am the first to use ametal with Insulin modified by the addition of the aforesaid reactionproduct, as well as the first to modify Insulin by the addition of suchreaction product.

The final product obtained, whether or not a metal is used, may beadministered-in water either subcutaneously or intramuscularly, andproduces a lowering of the blood-sugar level of longer duration thandoes ordinary Insulin. The hydrogen ion concentration may be adjusted asdesired, and the product may be used with safety and effectivenesswhether it is a solution or a suspension. For instance: It may beadjusted to about pH 3.0 to pH 4.0, in which range the product isusually in solution, and so administered; with excellent results inprolonging the Insulin effect. Or, it may be adjusted to about pH 6.0 topH 8.0, in which range the product is usually mainly in suspension, andso administered; generally with rather greater prolongation of Insulinefiect than on administration of the same product in solution.

I claim as my invention:

1. The process of producing an Insulin preparation which has a prolongedphysiological effect, which consists in putting together Insulin and thereaction product of a substance of the class consisting of formaldehydeand its polymers with a guanidine salt.

2. The process of producing an Insulin preparationwhich has a prolongedphysiological effect, which consists in putting together Insulin and thereaction product of a substance of the class consisting of formaldehydeand its polymers with guanidine carbonate.

3. The process of producing an Insulin preparation which has a prolongedphysiological effeet, which consists in putting together Insulin and thereaction product of a substance of the class consisting of formaldehydeand its polymers, with guanidine.

i. A composition of matter, consisting .of the resultant productobtained by mixing Insulin and the reaction product of a substance ofthe class consisting of formaldehyde and its polymers with a guanidinesalt. I

5. A composition of matter, consisting of the resultant product obtainedby mixing Insulin and the reaction product of a substance of the classconsisting of formaldehyde and its poly mers with guanidine carbonate.

6. A composition of matter, consisting of the resultant product obtainedby mixing Insulin and the reaction product of a substance of the classconsisting of formaldehyde and its poly mers with guanidine.

'7. The process of producing an Insulin preparation which has aprolonged physiological effect, which consists in putting togetherInsulin and the reaction product of a substance of the class consistingof formaldehyde and its polymers with a substance of the classconsisting of guanidine, its salts, and the guanidine derivativesdecamethylenediguanidine dihydrochloride and 4,4'-dig-uanidodiphenyldihydrochloride.

8. A composition of matter, consisting of the resultant product obtainedby mixing Insulin and the reaction product of a substance of the classconsisting of formaldehyde and its polymers with a substance of theclass consisting of guanidine, its salts, and the guanidine derivativesdecamethylenediguanidine dihydr'ochloride and 4,4'-diguanidodiphenyldihydrochloride.

GEORGE B. WALDEN.

